Bar lock for grain hammermills



Jan. 2, 1962 s. c. JENSEN 3,015,452

BAR LOOK FOR GRAIN HAMMERMILLS Filed Dec. a, 1958 FIG. I

/INVENTOR. SANNNG c. JENSEN United States Patent 3,015,452 BAR LOCK FOR GRAIN HAMMERMILLS Sanning C. Jensen, Neola, Iowa Filed Dec. 8, 1958, Ser. No. 778,909 1 Claim. (Cl. 241-194) This invention relates to grain hanimermills and more particularly it is the purpose of this invention to provide a lock for firmly gripping bars about which the hammers swing and maintaining such bars in place in the barholding members of the mill.

Heretofore costly trouble was involved whenever it was necessary to replace a grain hammermill knife. To accomplish this replacement it was necessary to unscrew a nut at one end of the hammer holding bar which is disposed at one end of the machine and then go a considerable distance, if a large machine, to its other end to remove a nut at the other end of the bar in order to permit free sliding of the bar in either direction for the removal and replacement of certain defective hammers on one end or other of the bar.

It is usual that all cutting knives of a grain hammermill need not be replaced at one time and therefore the shutting down of a grain hammermill and the unscrewing of nuts at the ends of the cutting hammer bar must be done very frequently. The frequency in number of shut downs is very costly in lack of hammermill production and is therefore very expensive in large installations.

Heretofore no way has been found to eliminate the need for the time-consuming method of unscrewing of bolts and nuts from each end of the cutting bar. It is my concept and it is an object of my invention to provide a hammermill bar lock adapted to grip about the cutting knife bar with such great force as to effectively bear against a side surface of a cutting knife arm so as to prevent the knife holding head from moving lengthwise of itself out of position in the hammermill.

A further object is to provide a bar lock, two of which can be used in cooperation at one end of the knife-holding bar for preventing the bar from sliding in either'direction, the bar locks being removable from their corresponding position for release of the bar to permit inten' tional lengthwise sliding of the bar whereby an operator can release the bar by merely releasing two bar locks at one end of the bar.

In the prior art installations in which nuts are not used at the ends of the bar, set screws are commonly employed. These set screws wear away due to the abrasive action of the grain and foreign matter therein so seriously that it is difficult to apply a tool to them for removal, leading to high repair cost problems which it is an object of ms invention to eliminate.

As bar locks wear away in use, it is a particular object to provide a bar lock of economical construction.

A further object of my invention is to provide a device which is simple in construction, easy to operate and extremely efiicient for the purposes described in practical use.

Other and further objects and advantages of the instant invention will be apparent from the following described drawings and claims, the scope of the invention not being limited to the drawings themselves as the drawings are only for the purpose of illustrating the best way in which the principles of this invention can be applied.

Other embodiments of the invention utilizing the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.

In the drawings:

FIGURE 1 is a top plan view of a portion of a hammermill, including a portion of the housing thereof,

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a portion of the rotor shaft, and an end portion of the hammer securing bar shown with two bar locks of this invention secured around the bar.

FIGURE 2 is a detail taken along the FIGURE 1.

FIGURE 3 is a plan view similar to that shown-in FIGURE 1 showing a modification wherein a single knife is used instead of a double knife.

The bar lock of this invention is for attachment toahammermill, a portion of the housing 10 of which is shown in FIGURE 1 and, the remainder of the hammer-v mill not being shown.

The hammermill is provided with a central rotor shaft 14 which is provided with a plurality of pairs of arms 20 which are attached thereto and which extend upward- 1y therefrom. The arms 20 are arranged in pairs, three pairs of which are shown in FIGURE 1, and it will be understood that many pairs are present in a larger hammermill.

The hammermill is provided with a knife bar 30 extending through the ends of the arms 20 and positioned parallel to the central rotor shaft 14.

Between each pair of arms 20 are one or more, and preferably two, cutting knives 50 each of which is provided with openings for receiving the knife bar 30 therethrough, whereby the knife bar can swing.

In the design shown in FIGURE 3 a single knife 40 is held by a substantially U-shaped adapter or resilient holding element 42 between arms 20 extended from the rotor shaft 14 and through which the knife bar 46 similar to the bar 30 extends. The parts are retained in spaced relation by the bar locks 60.

Bar locks 60 of this invention are shown against oppositely facing sides of two adjacent pairs of arms 20, as best seen in FIGURE 1, whereby the bar locks 60 prevent unwanted lengthwise sliding movement of the bar 30. As best seen in FIGURE 2, each bar lock 60 is formed of a single piece of resilient material such as spring steel or steel of sufficient resiliency and strength of grip that a loop section 62 thereof, forming a central portion of the bar lock, tends to grip the bar 30 in a vicelike fashion as the loop 62 tends to seek its normal position. The normal inside diameter of a loop is substantially less than the outside diameter of the bar 30. The loop portion 62 is preferably circular when used on a circular bar so as to grip around the majority of the inner surface of the loop. No matter what shape the bar is, the loop is preferably of a shape complementary thereto. However, it will be understood that in hammermills the bars 30 are always round in cross section. Theterminal end sections 70 are disposed approximately radially with respect to the circular central loop portion 62.

The terminal ends 70 are spaced apart a substantial distance even after the bar lock has been placed on the bar 30 whereby the application of a pair of pliers on the outer sides of the terminals ends 70 will make possible the forcing of the terminal ends 70 toward each other to cause the central loop portion 62 of the bar lock to expand to a larger diameter for the release of the bar locks tight grip on the bar 30.

'It is this latter characteristic of the bar lock that permits its insertion into and removal from the positions shown in FIGURE 1.

From the foregoing description, it is thought to be obvious that a bar lock for grain hammermill constructed in accordance with my invention is particularly well adapted for use by reason of the convenience and facility with which it may be assembled and operated, and it will also be obvious that my invention is susceptible of some change and modification without departing from the principles and spirit thereof, and for this reason I do not wish to be understood as limiting myself to the precise arline 22 of rangement and formation of the several parts herein shown in carrying out my invention in practice, except as claimed.

I claim:

-In a hammer-mill knife mounting, the combination which comprises a hammermill rotor shaft, spaced pairs of arms mounted on and extended from the rotor shaft, a knife barextended through and carried by extended ends of the arms, a knife mounted on the knife bar and positioned between the arms, said knife bar being longitudinally slidable through said arms of said pairs of ends,

and at least one bar lock disposed around said knife bar, said bar lock comprising at least one loop formed of resilient material which is biased to cling to said bar with sufiicient force for restricting longitudinal movement of said knife bar through said arms, said knife bar having a smooth cylindrical surface adjacent said bar lock.

References Cited in the file of this patent UNITED STATES PATENTS 1,073,850 Greer Sept. 13, 1913 1,348,751 Searby Aug. 3, 1920 2,044,531 Kaspar June 16, 1936 2,348,916 Magnus May 16, 1944 2,524,562 Dawbarn Oct. 3, 1950 2,810,529 Jensen Oct. 22, 1957 FOREIGN PATENTS 662,128 Germany July 5, 1938 

